Philodromidae
Running Crab Spider Identification Australia
A running crab spider is a fast, non-web-hunting member of Philodromidae; confirm the family cautiously, because many Australian spiders run on bark, foliage and walls.
Usually low risk“Running crab spider” is the common family-level label for Philodromidae, not a single Australian species. They are agile hunters that do not use silk to catch prey and may be found on vegetation, bark or a wall. That lifestyle and a crab-like outline can be useful first clues, but they also overlap with true crab spiders, lynx spiders, small huntsmans and several unrelated active hunters. A phone photograph rarely shows the adult anatomical characters needed for a species name, so this page deliberately stops at family level and keeps the image placeholder rather than presenting one species as the family.
Quick identification
- An active hunter rather than a spider sitting in an orb, sheet, funnel or messy prey-catching web
- A relatively flat, pear-shaped front body and oval to elongate abdomen can fit Philodromidae, but are not diagnostic from one angle
- Legs may look long and forward-directed; Lucid’s Australian treatment notes that leg I and/or II can be longest
- A clear adult whole-body view plus locality and habitat; eye and reproductive characters are often needed to go further
- No claim that a single photographed species represents this family-level page
What to check next
Record body length separately from leg span, a whole upper view, a side view, the exact locality and whether the spider was on foliage, bark or a building. Compare the true crab-spider, slender-crab, square-ended and trapezoid-crab pages, but retain a broad active-hunter identification when the eye pattern and adult anatomy are not visible.
When to seek medical help
Usually low risk. For a witnessed non-funnel-web bite, healthdirect advises washing with soap and water, using a wrapped cold pack for swelling and seeking medical care if pain is severe or persistent, swelling worsens or the person feels unwell. Call 000 for breathing difficulty, collapse or other signs of anaphylaxis. Do not handle a spider to improve an identification.
Where it is usually seen
Vegetation, open eucalypt forest, bark, grass, low shrubs, fences and walls. The exact setting varies by taxon, so a spider on one leaf or wall is not enough to confirm Philodromidae.